Marxism and science

Every materialistic philosophy is based in the developement of
science. The developement of science directly affects the thinking of
philosophy. In other words one of the major basis of philosophy is
science. So materialism is the generalized version of science. And the
latest and the most discussed materialistic philosophy is Marxism. But
the opponents of marxism refuses the relation of marxism and science.
This is either their lack of philosophical education or their
intention of refusing of marxism. But one who really loves science and
study philosophy then he will easily find the relation between them.
Marxism believes in struggle between opponents from atom to galexy to
human beings. He check the law of "conversion of quality to quantity
and quantity to quality" in water even in periodic table then in human
society. Then how can it be said in against of scientific
developement?